For 200 years, the corrido served as the soundtrack to Mexico's tempestuous history. Often written by the poor at the expense of the powerful, the folk ballads spoke of revolution and social justice, of heroism in battle and cowardice behind the palace walls, all set to a buoyant rhythm.

In recent years, many prominent corridos have been exercises in vanity in three-quarter time — narco-corridos commissioned to celebrate the exploits not of Pancho Villa or Francisco Madero but of drug traffickers.

It was left to a town on the north side of the border to offer a reminder of what the corrido has been, and can be.

A faction of El Paso has come to believe that a local son, 34-year-old Daniel Villegas, has spent half his life in prison for two murders he did not commit. The case has struck a chord in El Paso, literally. A corrido about Villegas' case is popping up on the radio, on the Internet and in CD players, serving as an unusual anthem for an unlikely movement.

It was written by Ernesto Martinez, a manager at a construction company by day, a gifted norteno-style accordion player by night, who performs under the moniker El Zorro de Chihuahua. When he first heard of the Villegas case, Martinez didn't think much of it because of one simple fact — Villegas had confessed to the killings. Then he heard the rest of the story and determined, he said, "that it all started with a lie."

He began to write.

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The laws of the United States of America

Indeed very powerful

But there are times they fail.

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A few years ago, an El Paso businessman named John Mimbela fell in love with a woman who was a teller at his bank. They married, and Mimbela adopted her three daughters. Mimbela soon learned that the girls' uncle was in prison — and, according to the family, he was innocent.

A devout Catholic, Mimbela believed in second chances, and employed a number of ex-cons at Mimbela Contractors Inc. He too was skeptical when he heard about Villegas' case, well aware of the old sarcastic saw — that everyone in prison is innocent. But he agreed to take a look.

Like him, Villegas grew up in a tough neighborhood known as the Devil's Triangle. Villegas was never able to sit still in school. He dropped out before high school, with a third-grade reading level. He glamorized the life of the streets, where he was known as Danny Boy. But the worst crime he got booked on was a curfew violation.

Often, Villegas tried to make his life sound more interesting than it was. He bragged to friends that he slept on a water bed, that he was descended from Italian royalty, that he owned a fancy stereo — none of which was true. He was, as his little sister put it, "a liar," and as his mother put it, "a pain in the butt."

So in the spring of 1993, after two teenagers were killed in a sandy lot off Electric Avenue, some thought it was just more bragging when Villegas, then 16, boasted that he'd pulled the trigger. The police, however, were not ready to ignore Villegas' claims.

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Whenever there is a murder

Someone is to be blamed.

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Though it abuts Juarez, Mexico, one of the most dangerous places in the world, there were just five homicides last year in El Paso. It was a very different place in 1993. That year there were 56 homicides, most attributed to gang warfare.

The drive-by shootings of Robert England, 18, and Armando Lazo, 17, left no physical evidence beyond shell casings. But authorities had Villegas' one-page confession, dictated in the language of a schoolboy. In it, he couldn't spell his father's first name, though he did note that a detective had given him a Coke. The confession did not offer a motive for the crime, other than a desire to frighten the victims.

"Give their families my regrets," the confession concluded. "I would not of done it, but I wanted to scare them."

Villegas later recanted, asserting that he had confessed under duress and in fact had been baby-sitting with friends across town at the time of the shootings. Still, he was charged with capital murder. El Paso County Dist. Atty. Jaime Esparza, who was newly elected, personally tried the case.

Prosecutors painted the crime as a drive-by shooting carried out by members of one gang against neighborhood rivals. Villegas' first trial ended in a hung jury. At the second trial, in 1995, a jury deliberated for three hours before finding him guilty. He was sentenced to life in prison.

Years later, Mimbela began poring over court records. He learned that Villegas had bragged to a relative that he'd used a shotgun — the boast that sparked a round of gossip that led to his arrest. But the murder weapon was a small-caliber handgun.

According to interviews and court documents, Villegas' confession also did not jibe with some of the facts.